Native sql (本地sql)在Hibernate中

Native sql 本地sql在Hibernate中

http://www.hibernate.org/hib_docs/v3/reference/en/html/querysql.html

使用SQLQuery

<!--[if !supportLists]-->1. <!--[endif]-->标量查询scalar query

如

sess.CreateSQLQuery("SELECT * FROM CATS")

 .AddScalar("ID", NHibernateUtil.Int64)

 .AddScalar("NAME", NHibernateUtil.String)

 .AddScalar("BIRTHDATE", NHibernateUtil.Date)

返回List的Object[]，每个Object有上述三个字段组成。

<!--[if !supportLists]-->2. <!--[endif]-->Entity query

如

sess.CreateSQLQuery("SELECT * FROM CATS").AddEntity(typeof(Cat));

sess.CreateSQLQuery("SELECT ID, NAME, BIRTHDATE FROM CATS").AddEntity(typeof(Cat));

返回List的Cat[]。

<!--[if !supportLists]-->3. <!--[endif]-->处理association和collections

如

sess.CreateSQLQuery("SELECT c.*, m.* FROM CATS c, CATS m WHERE c.MOTHER_ID = c.ID")

.AddEntity("cat", typeof(Cat))

.AddEntity("mother", typeof(Cat))

每行将返回两个Cat对象：一个Cat，一个Cat的mother。

但是上面的代码会造成列名的冲突问题。

因此：

sess.CreateSQLQuery("SELECT {cat.*}, {mother.*} FROM CATS c, CATS m WHERE c.MOTHER_ID = c.ID")

.AddEntity("cat", typeof(Cat))

.AddEntity("mother", typeof(Cat))

<!--[if !supportLists]-->4. <!--[endif]-->alias和property引用

Description	Syntax	Example
A simple property	{[aliasname].[propertyname]}	A_NAME as {item.Name}
A composite property	{[aliasname].[componentname].[propertyname]}	CURRENCY as {item.Amount.Currency}, VALUE as {item.Amount.Value}
Discriminator of an entity	{[aliasname].class}	DISC as {item.class}
All properties of an entity	{[aliasname].*}	{item.*}
A collection key	{[aliasname].key}	ORGID as {coll.key}
The id of an collection	{[aliasname].id}	EMPID as {coll.id}
The element of an collection	{[aliasname].element}	XID as {coll.element}
property of the element in the collection	{[aliasname].element.[propertyname]}	NAME as {coll.element.Name}
All properties of the element in the collection	{[aliasname].element.*}	{coll.element.*}
All properties of the the collection	{[aliasname].*}	{coll.*}

<!--[if !supportLists]-->5. <!--[endif]-->得到non-managed entities

处理继承

native sql查询的实体是一个继承结构中的一部分的话，就必须包括进来其基类和子类的属性。

<!--[if !supportLists]-->6. <!--[endif]-->参数

Query query = sess.CreateSQLQuery("SELECT * FROM CATS WHERE NAME like ?").AddEntity(typeof(Cat));

IList pusList = query.SetString(0, "Pus%").List();

query = sess.createSQLQuery("SELECT * FROM CATS WHERE NAME like :name").AddEntity(typeof(Cat));

IList pusList = query.SetString("name", "Pus%").List(); 

Named sql queries

<!--[if !supportLists]-->1. <!--[endif]-->Scalar query

<sql-query name="mySqlQuery">

 <return-scalar column="name" type="String"/>

 <return-scalar column="age" type="Int64"/>

 SELECT p.NAME AS name,

 p.AGE AS age,

 FROM PERSON p WHERE p.NAME LIKE 'Hiber%'

</sql-query>

<!--[if !supportLists]-->2. <!--[endif]-->Entity query

<sql-query name="persons">

 <return alias="person" class="eg.Person"/>

 SELECT person.NAME AS {person.Name},

 person.AGE AS {person.Age},

 person.SEX AS {person.Sex}

 FROM PERSON person

 WHERE person.NAME LIKE :namePattern

</sql-query>

IList people = sess.GetNamedQuery("persons")

 .SetString("namePattern", namePattern)

 .SetMaxResults(50)

 .List();

return的含义：这个查询返回一个alias的实体。

<!--[if !supportLists]-->3. <!--[endif]-->return-join和load-collection

<sql-query name="personsWith">

<!--[if gte vml 1]><v:line
 id="_x0000_s1028" style='position:absolute;flip:y;z-index:3' from="39.6pt,13.8pt"
 to="48.6pt,45pt" coordsize="21600,21600">
 <v:stroke endarrow="block" />
</v:line><![endif]--><!--[if !vml]--><!--[endif]--> <return alias="person" class="eg.Person"/>

<!--[if gte vml 1]><v:line
 id="_x0000_s1027" style='position:absolute;flip:x y;z-index:2' from="30.6pt,13.8pt"
 to="66.6pt,84pt" coordsize="21600,21600">
 <v:stroke endarrow="block" />
</v:line><![endif]--><!--[if !vml]--><!--[endif]--> <return-join alias="address" property="person.MailingAddress"/>

 SELECT person.NAME AS {person.Name},

 person.AGE AS {person.Age},

 person.SEX AS {person.Sex},

 adddress.STREET AS {address.Street},

 adddress.CITY AS {address.City},

 adddress.STATE AS {address.State},

 adddress.ZIP AS {address.Zip}

 FROM PERSON person

 JOIN ADDRESS adddress

 ON person.ID = address.PERSON_ID AND address.TYPE='MAILING'

 WHERE person.NAME LIKE :namePattern

</sql-query>

return-join和load-collection都可以参照第一部分中的assocation和collection。

<!--[if !supportLists]-->4. <!--[endif]--><!--[if gte vml 1]><v:line
 id="_x0000_s1026" style='position:absolute;left:0;text-align:left;flip:x y;
 z-index:1' from="30.6pt,-245.7pt" to="147.6pt,3.9pt" coordsize="21600,21600">
 <v:stroke endarrow="block" />
</v:line><![endif]--><!--[if !vml]--><!--[endif]-->利用resultset扩展关于结果集映射（参考上面的return和return-join）的信息

<resultset name="personAddress">

 <return alias="person" class="eg.Person"/>

 <return-join alias="address" property="person.MailingAddress"/>

</resultset>

<sql-query name="personsWith" resultset-ref="personAddress">

 SELECT person.NAME AS {person.Name},

 person.AGE AS {person.Age},

 person.SEX AS {person.Sex},

 adddress.STREET AS {address.Street},

 adddress.CITY AS {address.City},

 adddress.STATE AS {address.State},

 adddress.ZIP AS {address.Zip}

 FROM PERSON person

 JOIN ADDRESS adddress

 ON person.ID = address.PERSON_ID AND address.TYPE='MAILING'

 WHERE person.NAME LIKE :namePattern

</sql-query>

用程序的方式处理上面的配置信息：

IList cats = sess.CreateSQLQuery(

 "select {cat.*}, {kitten.*} from cats cat, cats kitten where kitten.mother = cat.id"

 )

 .SetResultSetMapping("catAndKitten")

 .List();

<!--[if !supportLists]-->5. <!--[endif]-->显示指定结果集中的column的显示名字（return-property）

<sql-query name="mySqlQuery">

 <return alias="person" class="eg.Person">

 <return-property name="Name" column="myName"/>

 <return-property name="Age" column="myAge"/>

 <return-property name="Sex" column="mySex"/>

 </return>

 SELECT person.NAME AS myName,

 person.AGE AS myAge,

 person.SEX AS mySex,

 FROM PERSON person WHERE person.NAME LIKE :name

</sql-query>

将多column映射为一个名字

<sql-query name="organizationCurrentEmployments">

 <return alias="emp" class="Employment">

 <return-property name="Salary">

 <return-column name="VALUE"/>

 <return-column name="CURRENCY"/>

 </return-property>

 <return-property name="EndDate" column="myEndDate"/>

 </return>

 SELECT EMPLOYEE AS {emp.Employee}, EMPLOYER AS {emp.Employer},

 <place><city><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'>STARTDATE</span></city><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'> </span><state><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'>AS</span></state></place> {emp.StartDate}, <place><city><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'>ENDDATE</span></city><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'> </span><state><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'>AS</span></state></place> {emp.EndDate},

 REGIONCODE as {emp.RegionCode}, <place><city><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'>EID</span></city><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'> </span><state><span lang="EN-US" style='font-size: 10.5pt; font-family: "Courier New";'>AS</span></state></place> {emp.Id}, VALUE, CURRENCY

 FROM EMPLOYMENT

 WHERE EMPLOYER = :id AND ENDDATE IS NULL

 ORDER BY STARTDATE ASC

</sql-query>

<!--[if !supportLists]-->6. <!--[endif]-->stored procedures

<sql-query name="selectAllEmployments_SP">

 <return alias="emp" class="Employment">

 <return-property name="employee" column="EMPLOYEE"/>

 <return-property name="employer" column="EMPLOYER"/>

 <return-property name="startDate" column="STARTDATE"/>

 <return-property name="endDate" column="ENDDATE"/>

 <return-property name="regionCode" column="REGIONCODE"/>

 <return-property name="id" column="EID"/>

 <return-property name="salary">

 <return-column name="VALUE"/>

 <return-column name="CURRENCY"/>

 </return-property>

 </return>

 exec selectAllEmployments

</sql-query>

stored procedures的使用有一些限制，如果不遵守，就不能在Hibernate中使用stored procedures，而只能用session.connection()。限制根据db的不同而不同，因为不同的db中stored procedures有差别。

Stored procedure queries can't be paged with setFirstResult()/setMaxResults().

Recommended call form is standard SQL92: { ? = call functionName(<parameters>) } or { ? = call procedureName(<parameters>}. Native call syntax is not supported.

For Oracle the following rules apply:

<!--[if !supportLists]-->· <!--[endif]-->A function must return a result set. The first parameter of a procedure must be an OUT that returns a result set. This is done by using a SYS_REFCURSOR type in Oracle 9 or 10. In Oracle you need to define a REF CURSOR type, see Oracle literature.

For Sybase or MS SQL server the following rules apply:

<!--[if !supportLists]-->· <!--[endif]-->The procedure must return a result set. Note that since these servers can/will return multiple result sets and update counts, Hibernate will iterate the results and take the first result that is a result set as its return value. Everything else will be discarded.

<!--[if !supportLists]-->· <!--[endif]-->If you can enable SET NOCOUNT ON in your procedure it will probably be more efficient, but this is not a requirement.

Custom sql for create, update ,delete, loading